Raising machines for textile and other fabrics



June 27, 1961 N. PILKINGTQN .rAL 2&989795 RAISING MACHINES FOR TEXTILE AND OTHER FABRICS 2 Sheets-Sheet 1 Filed March 27, 1956 mam-nrs j .Sohn Mahul DavuA. MWA Rob Bymwm 99mm June 27, 1961 Ni PM KINGTON nrs1' AL RAISING MACHINES FOR TEXTILE AND OTHER FABRICS 2 Sheets-Sheet 2 Filed March 27, 1956 n d0 A@ l b Mm kJ. .01+ JJMQ/ h On .,mdS m5 n `\am Kl n vwwm .n mm me.. o T d Na@ n a D United States Patent 2,939,795 RAISING MACHINES FOR TEXTILE AND OTHER FABRICS Norman Pilkington, Chadderton, `lohn Michael Dania Tomlinson, Milnrow, and Richard Robinson Clegg, Rochdale, England, assignors to Tomlinsons (Rochdale) Limited, Rochdale, England, a British company Filed Mar. 27, 1956, Ser. No. 574,242 Claims. (Cl. 26-34) This invention relates to wire card raising machines, both to single action machines, and more particularly to the so-called double-action raising machines Which comprise a cylinder of large diameter about the peripheral surface of which are longitudinally mounted any number of alternate pile and counter-pile rollers, Such a machine will hereinafter be referred to as a raising machine of the type described.

The pile `and counter-pile rollers are surfaced with card clothing, the wires of the pile rollers pointing in the direction of travel of the cloth and the wires of the counter-pile rollers pointing in the opposite direction, that is to say, against the direction of travel of the cloth. The pile rollers, and the counter-pile rollers are driven at speeds other than the speed at which a web of textile material is fed over the cylinder, and the cylinder is rotated in the same direction of travel of the cloth therearound and at a peripheral speed faster than the speed of the cloth. This has the result that the wires of the pile and counter-pile rollers attack and draw the weft, and to a lesser extent the warp threads of the cloth, so achieving a raising action.

The pile and counter-pile rollers are usually but not necessarily driven yfrom the same source of power as drives the cylinder. This is usually achieved by providing two sprockets on a suitable shaft, chains on said sprockets being adapted to drive the pile and counterpile rollers each through infinitely variable gearboxes.

Before the conception of this invention the control of and particular raising machine and the effects produced when treating any particular fabric was entirely dependent upon the ability of the operator in charge of the machine to ascertain the rates at which the pile and, if present, counter-pile rollers should be driven to obtain a so-called zero raising action.

In theory, such zero raising action could be obtained if all external sources of power, friction, and the like were taken away from all the rollers, and the web merely passed over the cylinder (whilst the latter is rotating) so that the only drive imparted to the rollers is from the web. This, of course, is impossible, since the friction of the roller bearings ctc., could not be eliminated in practice.

It would be possible to obtain an approximation of the Zero values by disconnecting the drive to the rollers, measuring the speed of rotation thereof when driven only by the cloth web, and calculating the subsequent desired driving speeds for the rollers from the result so obtained; and there have been many proposed arrangements with this in view.

However, since the zero raising conditions vary with the material being treated, and even with different batches of the same material, there are obvious disadvantages in adopting this method of approach, especially where the conditions arrived at are only approximate, since the zero raising conditions have to be recalculated frequently, at least with each fresh batch of material.

Similarly, in use, the wires of the card clothing wear, and this obviously has an effect on how the cloth engages therewith, so making frequent re-checks of the zero raising conditions essential.

It is` an object of the present invention to provide "ice means whereby the zero raising conditions can be ascertained for any particular textile material or for any particular condition of the machine, or both, whilst the machine is in operation, and without the need of disconnecting the drive to the rollers, or for making any calculations or comparisons.

To this end, there is provided a wire card raising machine wherein there is provided for the pile rollers or the counter-pile rollers, or both, a device adapted to provide indication when the rollers are being driven at the appropriate speeds to give zero raising action, such indication being visible, audible or otherwise discernible without the need of mental calculation or comparison.

Where the rollers are driven by means of chains passing over a sprocket on the cylinder shaft, the device or devices may conveniently be associated with the respective chains so as to provide the visual indication according to the tensions of said chains.

The invention will be described further, by way of example, with reference to a preferred form thereof as applied to a double action raising machine, and the accompanying drawings in which:

FIG. 1 is a plan view of a double acting raising machine constructed in accordance with one form of the invention.

FIG. 2 is an elevation of the machine shown in FIG. 1, and

FIG. 3 is an enlarged elevation of part of FIG. 2 showing diagrammatically one system for indicating working conditions of the machine by visual means.

The machine comprises basically a framework 10 upon which is rotatably mounted a cylinder 11 having around its periphery a number of rotatable rollers (for example, thirty-six) each of which is covered with card clothing (not shown). The rollers are arranged in two sets, one set 13 having the card clothing arranged therearound in such a manner that the points lie in the direction of rotation of the rollers, and the other set 12 having the points of the card clothing arranged to lie in the opposite direction to the direction of rotation of the rollers. These rollers are named respectively the counter-pile and pile rollers and they are arranged alternately around the cylinder. The cylinder 11 is mounted on a shaft 14 and in the drawings is arranged to rotate in an anti-clockwise direction, vthe pile and counter-pile rollers rotating in a clockwise direction. Drive for the cylinder 11 is taken `from a suitable motor (not shown). Adapted to 'rotate with, but in the opposite direction to the cylinder 11 are two large gear wheels 15 each having four brackets 16 thereon, one only of which is shown on each gear Wheel, at to4 each other. Attached to the brackets 16 are four V-belts 1'7, each of which extends over 180 and each of which overlaps the adjacent belt by 90. 'I'he V belts 17 pass over V-pulleys 18 on the, ends of the rollers 12 and 13, the arrangement being such that all the pile rollers 12 take their driveV from one end of the cylinder and one of the gear wheels 15 and the counterpile rollers 13 take their drive from the opposite end of the cylinder and the other gear-wheel 15.

The drive for the two gear Wheels 15 is obtained through chain drives from the shaft 14 through infinitely variable gearboxes 19 and 20. The gearbox 19. drives the gear-wheel 15 for the pile rollers 12 through sprocket 21 and the gearbox 20 drives the gear-wheel 15 for the counter-pile rollers 13 through sprocket 22. In each case each chainV passes over a sprocket 141 on the shaft 14 and over one ofthe complementary sprocketsv 123, 123f on the input shafts 23, 23 of the twogearboxes.

The gearboxes and their chain drives for the pile and counter-pile rollers 12 and 13 v will be considered separately. g

With a web of fabric (not shown) passing around the cylinder 11, and with the pile rollers 12 controlled from the gearbox 19 at diiferent speeds, various conditions are obtained and these are best considered by taking into account the difference in speed between the periphery of the cylinder 11 as a whole and the `fabric passing therearound. Since the cylinder 11 rotates faster than the fabric passing around it, it is most convenient in theory to consider the machine with the fabric stationary and the cylinder 11 rotating in what would normally be the direction of travel of the fabric.

The pile rollers 12 can now be driven or caused to rotate in the following ways:

(a) If no influence is applied to the pile rollers 12 by the gearbox 19, and gearbox 19 is disconnected then the pile rollers tend to rotate in a direction opposite to the rotation of the cylinder 11, and at the same peripheral speed, as the latter, by engagement with the stationary fabric. At this rotary speed, the wires of the rollers dependent upon the inherent friction of the moving parts merely contact the fabric and neither tend to pull the threads of the fabric or to skid thereon. Thus the wires have no action, and the so-ealled zero raising conditions are theoretically attained. The same conditions prevail if the drive means 15, 17, 21, 19 drive pile rollers 12 at this rotary speed.

(b) If the gearbox 19 is now adjusted so that the pile rollers 12 rotate slightly more slowly than in (a) above, then the points of the wires are carried forward by the cylinder 11 and dig into the fabric to give a raising action. Thus, it will be appreciated that to obtain raising, the gearbox 19 is used to brake the pile rollers 12 when raising occurs.

The above are the practical effects obtainable, and with which this invention is concerned, but for the sake of completeness, it is to be noted that two other theoretical conditions are obtainable, and these are:

(c) If the rotation of the pile rollers 12 is slowed down considerably from (b) above, or is stopped completely, then the wires embed themselves into the fabric deeply and tearing or vicious and fierce raising results to the detriment of the cloth, and,

(d) If the rollers 12 are driven faster than at (a) instead of being braked as in (b) above, then the wires merely skid over or brush the fabric with the back of the card points, and there is very slight tendency for the fabric to slow the rollers down. The term zero raising as used in this description does not refer to this condition, but only to condition (a).

Under working conditions, the raising is frequently judged by ear, so that an operator controlling the machine wherein the pile rollers 12 are rotating either as in (a) or (d) above adjusts the gearbox 19 to slow the rollers 12 down until a characteristic noise associated with the actual raising is attained.

Now referring to FIG. 3 and considering the chain driving the gearbox 19 for the pile rollers 12, this has two runs, and for the sake of clarity, they will be called driving run 24 and braking run 25 respectively. In operation, the driving run 24 is taut when the gearbox 19 is effectively driving the rollers as in (d) and the braking run 25 will be taut during condition (b) when gearbox 19 drives the pile rollers 12 to have a peripheral speed smaller than the speed in condition (a). During positive raising, condition (b), the cloth tends to move the points of pile rollers 12 at a higher speed, and drive 14, 141 drives sprocket 123 slower in the same direction. Consequently, a counter-clockwise torque acts on sprocket 123, in the same direction as the drive 14, 141 tightening braking run 25. During condition (d), the pile rollers 12 have a peripheral speed greater than the cloth speed, so that the cloth tends to slow down pile rollers 12. The torque exerted by the cloth on sprocket 12.3 acts in the opposite direction to drive 14, 14,1, that is in clockwise direction, so that the driving run 24 is taut.

In practice, it is found that when zero raising conditions are attained as in (a), the tension or tautness of both runs of the chain varies and uctuates roughly midway between slackness and tautness while the pile rollers are driven from gear box 19.

A device cO-operating with said chain and responsive to variations of tension therein is provided, and this may comprise a bell-crank lever 26 pivotally mounted on the machine frame 10, and having a wheel 27 on one arm 26a, which wheel 27 is conveniently arranged to engage the driving run Z4 of the chain, somewhat after the manner of a jockey-wheel. A spring 26d acts on the arm 26b. The third arm 26e of the bell-crank lever 26 may be arranged between two electrical switches 28 and 29, these switches being spaced apart and adapted to operate by engagement of the arm 26e therewith. The arrangement is such that when the driving run 24 of the chain is in tension the arm 26e will operate one switch (for example 29) and complete a circuit to an indicator 4lamp 30, which may, for example, be green in color; when the chain is fluctuating, as explained above, then the circuit to the green lamp 30 will be broken and a circuit made to a second lamp 31, which may be yellow. Finally, when the driving run 24 of the chain is slack the arm 26e will engage the other switch 28 and so make a circuit to a third lamp 32 which may be red.

The operation of the device will be obvious. An operator intending to treat material with the machine can, at any time, ascertain the gearbox setting required to suit the machine and the material for zero raising of the pile rollers, merely by adjustment of the gearbox setting until the yellow light is lit. Desired raising effects can then be obtained merely by reducing the speed of the pile rollers by a desired or predetermined amount whereby the red lamp 32 will be illuminated and may be flashing alternately with the yellow lamp 31.

The conditions occurring at the counterpile rollers 13 are slightly different. Again considering the machine with the fabric stationary and the cylinder 11 rotating beneath it, the following conditions can occur:

(i) If the counter-pile rollers 13 do not rotate on the cylinder 11, or rotate in clockwise direction opposite to the rotation of the cylinder 11, only slowly, they merely skid over or brush the fabric with the back of the card points by virtue of the rotation of the cylinder itself. there is a slight tendency for the rollers 13 to be rotated by friction with the fabric, but this is negligible if the counter pile rollers are connected to drive means 15, 17. The term Zero raising as used in this description does not refer to this condition but only to the condition (ii) explained hereinafter.

(ii) If the counter-pile rollers 13 are driven at a peripheral speed equal to the peripheral speed of the cylinder 11, then the wires merely contact the fabric, but neither skid thereon nor tend to dig into the fabric, so that the zero raising condition of the counter-pile rollers 13 is attained. The same peripheral speed of the counter pile rollers 13 is obtained if they are disconnected from drive 15, 17, since they are rotated by the friction exerted by the cloth on the backs of the card points.

(iii) Now, if the speed of the counter-pile rollers 13 is slightly increased from (ii) above, the wires tend to bite into the fabric to pluck at the threads thereof which results in a raising action.

(iv) A fourth condition is theoretically possible wherein the counter-pile rollers 13 are rotated so fast that they embed themselves in the fabric and tear it but such is avoided in practice.

Now considering the driving chain to the counter-pile gearbox 20, when the counter-pile rollers 13 are driven slowly in clockwise direction as at (i) or at the same speed as the cylinder 11 as at (ii), the chain will always be under tension on its driving run 33, since the friction and inertia of the counter-pile rollers 13 has to be overcome, to rotate them by a torque acting in counterclockwise direction as viewed in FIG. 2, and the rollers are never driven by the relative movement of the cylinder 11 and the fabric. The run 34 of the chain never becomes taut since counter pile rollers 13 must always be driven by drive 14, 141.

During condition (iii), the cloth tends to slow down counter pile rollers 13 and produces a torque in opposite direction to the drive 14, 141. Therefore, the slack run 34 becomes slacker. In condition (i), the cloth tends to turn` the counter pile rollers faster than the drive 14, 141 and the torque produced by the cloth acts on sprocket 123' in the same direction as the drive 14, 141. so that the slack run 34 becomes tighter. During zero raising, condition (ii), no torque is produced by the cloth, and run 34 has an intermediate slackness. Due to the fact that the cloth acts `frictionally on the backs of the points of the counter pile rollers, there is never a positive engagement between the cloth and counter-pile rollers in condition i, ii, so that the torque produced by the cloth cannot exceed the torque of the drive 14, 141 whereby run 33 always remains taut.

The conditions prevailing at the pile rollers are different, since the pile rollers 12 move opposite to the cloth, and dig their points into the fabric in condition (b) so that the braking run 25 is tightened.

When the rollers 13 are speeded up to the conditions of (iii) above, the chain now has to provide additional power to rotate the rollers 13 because of the engagement of the Wires with the fabric, so the effect of adjusting the speed of the counter-pile rollers 13 from (ii) to (iii) above is to greatly increase the tension on the driving run 33 of the chain.

Mounted on the machine frame adjacent the chain driving the counter-pile roller gearbox 13 is a second bell-crank lever 35 similar to that at the chain for the pile roller gearbox 19, one arm 35a carrying -a jockey wheel 36 which rests on the driven run 34 of the chain about midway of its length, the other arm 35b being connected to a spring for holding wheel 36 on the chain, and a third arm 35e serving to operate switches 28', 29', and to illuminate, relative to conditions in the chain, lights 37, 38 and 39 which are respectively green, yellow and red.

However, since the driving run 33 will always be under tension, -as has been explained, the arrangement, instead of being responsive to visible slackness and tautness of the chain, has to be responsive to variations in tension in the driven run 34 of the chain. To this end, there is provided, a second bell-crank lever 40 having on one arm a jockey wheel 41 resting on the driving run 33 of the chain. On the other arm of the lever 40 is a spring 42 whereby the jockey wheel 41 is kept in contact with the chain. Without the pressure of roller 41, the slack of run 34 would not substantially change when the tension in the driving run changes. The pressure of roller 41 forms an angle in run 33 depending on the tension in run 33, so that the angle of run 34 is correspondingly varied, resulting in displacement of jockey wheel 36. For example, run 34 will be substantially straight in condition (i) since the driving run 33 is very little tensioned so that roller 41 depresses the center of run 33.

in use, the machine is run with the counter-pile rollers 13 driven slowly as in (i) above, and the load applied to the jockey wheel 41 maintains this latter in contact with the driving run 33 of the chain. With the wheel 41 loaded, when the speed of the counter-pile rollers 13 is increased rst as in (ii) then as in (iii) above then the additional tension occurring in run 33 will be sufficient to counteract the load on the jockey wheel 41, so causing the jockey wheel 36 to be displaced and the switches to be operated, causing one of the circuits to be made and the corresponding light to be illuminated. In condition (i), arm 35h will be lowered and operate the 4lower switch in FIG. 3 so that the green lamp 37 is on. In condition (iii), run 34 has the greatest slack, and arm 35b is raised and closes the upper switch to light the red lamp 39. In the connected.

In this instance, whilst there will only be a momentary intermediate condition of the chain, the switches again conveniently control three indicator lamps as described. Lamp 39 indicates that the counter-pile rollers are raising the cloth, and the other two indicating that no raising action is occurring. The zero condition is visually indicated by lamp 38. Elements 30-32 and 37-39 may be replaced by buzzers, if desired.

It will rbe appreciated that while raising machines may be employed for treatment of textile fabrics either of natural or synthetic fibres, it may be possible to treat other material produced in continuous webs with such a machine.

What we claim is:

l. A wire card raising machine having a framework, a large diameter cylinder including a driven cylinder shaft rotatably mounted in said framework, a plurality of pile land counter-pile rollers rotatably mounted on end portions of said cylinder and extending therebetween collectively to form the periphery of said cylinder, drive means for said pile and counter-pile rollers operatively connected to and driven by said Lcylinder shaft, and indication means operably associated with the drive from the cylinder shaft to said rollers and actuated from said rollers to give an indication when said rollers, and indication means operably associated with said rollers to give ya signal when said rollers are being driven -at appropriate speeds to give zero raising action, said indication means also being capable of indicating conditions other than that of zero raising.

2. A wire card raising machine having a framework, a large diameter cylinder including a driven cylinder shaft rotatably mounted in said framework, a plurality of pile and counter-pile rollers rotatably `mounted on end portions of said cylinder and extending therebetween collectively to form the periphery of said cylinder, drive means for said pile and counter-pile rollers, said drive means for said rollers comprising a pair of sprockets on said cylinder shaft, a chain passing around each of said sprockets, gearbox means driven by each of said sprockets, means connecting said gearbox means to said pile and counter-pile rollers, and indication means including a member adapted to be Kactuated by each of said chains, switches associated with each of said members to complete an electric circuit Iand give a signal when said rollers are being driven at appropriate speeds to give zero raising action, said indication means lalso being capable of indicating conditions other than that of zero raising.

3. A wire card raising machine having a framework, a large diameter cylinder including a driven cylinder shaft rotatably mounted in said framework, a plurality of pile and counter-pile rollers rotatably mounted on end portions of said cylinder 'and extending therebetween collectively to form the periphery of said cylinder, drive means for said pile and Counter-pile rollers, said drive means Ifor said rollers comprising a pair of sprockets on said cylinder shaft, la chain passing around each of said sprockets, an infinitely variable gearbox for each chain, a chain sp-rocket on each gearbox driven by its corresponding chain, a shaft driven from each gearbox, a pinion on each shaft, Ia gear wheel in mesh with each pinion, one of said gear wheels being associated with said pile rollers and the other of said gear wheels being associated with said counter-pile rollers, respectively, for driving said rollers, and'indication means including a bell-crank lever for each chain, a jockey wheel on one arm of each of said levers actuated by one of said chains, switches associated with each of the other arms of each of said bell-crank levers to complete an electric circ-uit and give -a signal when 'said lrollers are being driven at kappropriate speeds to give zero raising action, said indication means being capable of indicating conditions other than that of zero raising.

7 4. A wire card raising machine as set forth in claim 3 1n which said indication means comprises a buzzer systern.

5. A wire card raising machine having a framework, a large diameter cylinder including a driven cylinder shaft rotatably mounted in said framework, `a plurality of pile and counter-pile rollers rotatably mounted on end plates of said cylinder and extending therebetween coillectively to form the periphery of said cylinder, drive means for said pile and counter-pile rollers, said drive means for said rollers comprising a pair of sprockets on said cylinder shaft, a chain passing around each of said sprockets, an infinitely variable gearbox for each chain, a chain sprocket on each gearbox driven by its corresponding chain, a shaft driven from each gearbox, a pinion on each shaft, a gear wheel in mesh with each pinion, `one of said gear wheels being associated with said pile rollers and the other of said gear wheels being associated with said counter-pile rollers, respectively, brackets on each gear wheel, V-belts attached to said brackets, V-pulleys on said pile and counter-pile rollers driven by said V-belts of their corresponding gear wheel, and indication means including a bell-crank lever for each chain, a jockey wheel on one arm of each of said levers actuated by one of said chains, two switches `associated with each of the other arms of each of said bell-crank levers, movement of the latter arms being adapted to complete an electric circuit to give a signal when said rollers are being driven at appropriate speeds Ito give raising or zero raising action.

6. A wire card raising machine having a framework, a large diameter cylinder including a driven cylinder shaft rotatably mounted in said framework, a plurality of pile and counter-pile rollers rotatably mounted on end plates of said cylinder and extending therebetween collectively to form the periphery of said cylinder, drive means for said pile yand counter-pile rollers, said drive means for said rollers comprising a pair of sprockets on said cylinder shaft, a chain passing laround each of said sprockets, an infinitely variable gearbox for each chain, a chain sprocket on each gearbox driven by its corresponding chain, a shaft driven from each gearbox, a pinion `on each shaft, a gear wheel in mesh with each pinion, one of said gear wheels being 'associated with said pile rollers and the other of said gear wheels being associated with said counter-pile rollers, respectively, four brackets on each of said gear wheels, V-belts attached to said brackets each to extend over 180 `of its corresponding gear wheel and each to overlap the adjacent belt by 90, V-pulleys on said pile and counter-pile rollers driven by said V-belts of their corresponding gear wheel, and indication `means including a bell-crank lever for each chain, a jockey wheel on one arm of each of said levers actuated by `one of said chains, two switches associated with each of the other arms of said bell-crank levers, movement of either of the latter arms being adapted to complete an electric circuit to one of three differently colored indication lights to give a signal, in the form of one colored light, when zero raising action is attained, and to give, by means of the other two differently colored lights, an indication of the amount of work being done by the pile or counter-pile rollers respectively.

7. In a wire card raising machine having a set of pile rollers which treat textile material moved through said machine past said set of rollers at a preselected speed, in combination, variable driving means for rotating said set of rollers at selectively variable speeds; and indicating means controlled by said rollers and actuated through said driving means for indicating when said driving means is driving said set of rollers at zero raising speed in which the peripheral speed of said rollers is equal to said preselected speed of the textile material, and for indicating when said driving means is driving said set of rollers at least one other speed at which the peripheral speed of said rollers is lower than said preselected speed but above a predetermined minimum speed.

8. In a wire card raising machine having at least one set of napping rollers which treat textile material moved through said machine past said set of rollers at a preselected speed, in combination, variable driving means for rotating said set of rollers at selectively variable speeds; and indicating means controlled by said rollers and actuated through said driving means for indicating when said driving means is driving said set of rollers at zero raising speed in which the peripheral speed of said rollers is equal to said preselected speed of the textile material, and for indicating when said driving means is driving said set of rollers at least one other speed at which the peripheral speed of said rollers is higher than said preselected speed but below a predetermined maximum speed,

9. In a wire card raising machine having a set of pile rollers and a set of counter-pile rollers which treat textile material moved through said machine past said sets of rollers at a preselected speed, in combination, first variable driving means for rotating said set of pile rollers at selectively variable speeds; second variable driving means for driving said set of counter-pile rollers at selectively variable speeds; first indicating means controlled by said pile rollers and actuated through said first driving means for indicating when said first driving means is driving said set of pile rollers at zero raising speed in which the peripheral speed of said pile rollers is equal to said preselected speed of the textile material; and second indicating means controlled by said counter-pile rollers and actuated through said second driving means for indicating when said second driving means is driving said set of counterpile rollers at zero raising speed in which the peripheral speed of said counter-pile rollers is equal to said preselected speed of the textile material.

10. In a wire card raising machine having a set of pile rollers and a set of counter-pile rollers which treat textile material moved through said machine past said sets of rollers at a preselected speed, in combination, first variable driving means for rotating said set of pile rollers at selectively variable speeds; second variable driving means for driving said set of counter-pile rollers at selectively variable speeds; tirst indicating means controlled by said pile rollers and actuated through said first driving means for indicating when said first driving means is driving said set of pile rollers at zero raising speed in which the peripheral speed of said pile rollers is equal to said preselected speed of the textile material, and for indicating at least one other speed at which the peripheral speed of said pile rollers is lower than said preselected speed but above a predetermined minimum speed; and second indicating means controlled by said counter-pile rollers and actuated through said second driving means for indicating when said second driving means is driving said set of' counter-pile rollers at zero raising speed in which the peripheral speed of said counter-pile rollers is equal to said preselected speed of the textile material, and for indicating at least one other speed at which the peripheral speed of said counter-pile rollers is higher than said preselected speed but below a predetermined maximum speed.

References Cited in the tile of this patent UNITED STATES PATENTS 2,739,366 Dourdeville Mar. 27, 1956 FOREIGN PATENTS 401,895 Germany Sept. 9, 1924 679,825 Great Britain Sept. 24, 1952 696,437 Great Britain Sept. 2, 1953 986,644 France Apr. 4, 1951 UNITED STATES PATENT OFFICE CERTIFICATE oF CCRIIEC'I IO'I\Iv Patent No, ,2,989,795 June 27,1961

Norman Pilkington et al..

"It is hereby certified that error appearsv in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 6, lines 27 to 29v strike out "and indication means operably associated with said rollers to give a signal when said rollers" Signed and sealed this 21st dey of Novemberv 1961.

Attest: Y v

EBNESTW. SWIDER DAVID L. LADD Attesting Gffioer Commissioner of Patents 'usoMMbc 

